Valve for fire protection systems and methods of control therefore

ABSTRACT

A valve for control of fluid flow in a fire protection system, having a body forming a fluid path between an inlet and an outlet connected via a seat, and a clapper with a bottom sealing surface and a top with a latch abutment portion. The valve further comprises an arm coupled to the valve body about a hinge point and having a closure end with an optional roller or ball. The arm is movable to engage the clapper and maintain the clapper closed, or to disengage and allow the clapper to open. The arm is disposed such that the opening force on the clapper is transferred primarily directly to the body, providing large closing force against the clapper, requires relatively small force to dislodge the arm, and in many embodiments substantially isolates the closing force from the force required to dislodge the arm.

FIELD OF THE INVENTION

The present invention is directed generally to fire protection systemsand more particularly to improved valves in fire protection systems, andto methods of controlling thereof.

BACKGROUND OF THE INVENTION

Many fire protection systems use flow valves to control the flow ofamounts of water or other fire extinguishing agent (which, for brevity,will be equivalently related to as water in these specifications) to afluid distribution arrangement such as sprinklers, nozzles, and thelike, which distribute the water to where they are needed to extinguisha fire. Typically such a flow control valve has a valve body having achamber with an inlet and an outlet. The chamber forms at least aportion of a waterway which is a path for fluid flow from the inlet tothe outlet. The waterway has a sealing port defined therein, The valvehas a moveable closure member positioned in the waterway. The closuremember is movable between a closed position to at least one openposition. When the closure member is in the closed position the closuremember substantially obstructs (notwithstanding unintentional leaks andthe like) fluid flow from the inlet to the outlet, while in the openposition the closure member presents relatively low obstruction of suchfluid flow. Any number of intermediate closure member positions existbetween a closed and open state, but in most cases those positions aretransitory between the open and closed states, and as such would beconsidered in theses specifications as open states. The valve isconsidered closed when the closure member is in closed position, andopen when the closure member is not in the closed position, includingany intermediate states between the closed and the fully open position.

Operating such valves, especially when they are under high pressuredifferential, require large forces or large movement to change the valvefrom closed to open state, and/or to an intermediate state. To reducethe forces required to transition the valve from a closed to open state(and in certain cases from open to closed state, and/or to someintermediate state therebetween) controlled valves were developed.Controlled valves have a valve actuator mechanism which applies smallerforces in a judicial manner to control the movement of the closuremember in cooperation with other forces operating thereupon.

In certain valves known colloquially as ‘clapper’ type valves, theclosure member comprises a hinged member having a seal surface. In theclosed position the seal surface is urged against a valve seatsurrounding the sealing port, and blocks fluid flow from the inlet tothe outlet. In the open position, the closure member hereinafter knownas the clapper rotates about its hinge away from the seat, and thusallows fluid flow from the inlet to the outlet.

The following description relates to a valve which is exposed to fluidpressure from the inlet, and when the valve is in the closed state theclapper by blocking fluid flow prevents communication of pressure fromthe inlet to the outlet. Most common clapper type valves are installedin an orientation that will urge the clapper to close due togravitational forces, lacking other forces. Other mechanisms are alsoknown to apply forces that will urge the clapper to the closed position,but for brevity such mechanisms would be considered equivalent togravity, as their function is similar.

For clarity of the descriptive terms such as ‘upper’ and ‘lower’,‘above’, ‘below’, ‘sideways’, and the like, are applied to describerelative disposition, locations, and orientations of various components.Such terms should be construed as relating of a valve disposed in avertical position such that the outlet is above the inlet. Thus by wayof example the term ‘upper chamber’ relate to a volume bounded by thevalve body from the valve outlet to a plane dissecting the valve body ator about the sealing port, while the ‘lower chamber’ relate to a volumebounded by the valve body from the inlet to a plane dissecting the valvebody. Notably, the relative positions are descriptive and relative to avalve in the above described orientation and modifying the valveorientation would not change the disclosed relative structure. It ishowever noted that the sealing port may not be perpendicular to theinlet and the outlet.

In a system where the valve is disposed between a pressurized fluidsupply and the distribution network, the state where the valve is closedis equivalently referred to as standby state, and the state where thevalve is open is referred to as activated state. Reliable transitioningbetween standby and activated state during fire is perhaps the demand ofhighest importance of such valve, followed by avoiding false activationthereof.

When the valve is in standby state, inlet fluid pressure exerts anopening force which acts in an opening force direction against theclapper. The opening force may be very large, and without a closingactuator mechanism to oppose it, would overcome the gravitational forceapplied to the clapper. The closing mechanisms commonly utilize aclapper holding member to effect a closing force against the clapper.The clapper holding member may be actuated directly by an actuator suchas a piston, a screw, a diaphragm, and the like, or may be coupledindirectly to a control mechanism, often using mechanical advantage tocontrol the actuation of the closing member. Many types of actuatingmechanism are known, such as diaphragms, electric solenoids, electric,pneumatic, or hydraulic motors and pistons, and the like.

Valves often utilize mechanical advantage whereby the relatively smallforces generated by the control mechanism are multiplied by mechanicaladvantage thereby offsetting the large opening forces operating on theclapper in standby state. These valves sometimes experience restrictionof movement due to changes stemming from exposure to environmental orother factors that may cause resistance to movement. By way of example,corrosion or accumulations of adherent deposits may impede componentmotion, and such effects are particularly harmful when multiplied bymechanical advantage. Certain valves use resilient materials, and suchresilient materials experience reduction in resilience over time. Whensuch reduced resilience occurs in an element controlling valveoperations, especially when said effect is multiplied by mechanicaladvantage, resistance to opening increases significantly.

Other valves comprise elements that utilize mechanical advantage to holda flow control element closed either by having pressure operate over alarge area as in the case of the diaphragm, or by exerting force to acomponent or components having a large range of movement. Such largearea, or range of movement increase the overall volume of a valve makingit large and/or heavy, and making the valve more difficult to transportand install.

A common problem point in existing design is the interface where theretainer latch, retainer lever, piston, screw, or other similar retainermember abuts the clapper. At that area the retainer member must applylarge force to counter the large clapper opening force, and accordinglyreleasing the retainer member requires significant force which must beeffected by the control mechanism. As described supra, prior art valvesare susceptible to corrosion, deposits, loss of resilience, and similareffects, and attempts to ameliorate such problems require large size andweight increases. Moreover, most retainer members utilize mechanicaladvantage to achieve significant force, and oftentimes large range ofmotion, which slows down valve opening, and which requires largeactuator.

When transitioning between standby state and deployed state, many of theknown retaining members move generally in a direction which is oppositeto the direction of the force the retainer member applies to theclapper, in order to affect fluid flow. In certain other known valvesthe retainer member is a catch which is rotated away from the clapperbut the retainer member still moves firstly in the direction oppositethe closing force, in order to affect flow. In those known valves theactuating mechanism of the retainer member must bear at least asignificant portion of the opening force. In some known valvesmechanical advantage is used to reduce those forces operating on thecontrol mechanism, but as discussed above, such valves suffer severaldisadvantages such as slower actuation, and the effects of even smallresistance is amplified which reduces the valve reliability.

There is therefore a clear, yet heretofore unanswered, need for areliable valve and valve control mechanism which will overcome theshortcoming of known valves. Different aspects of the present inventionare directed to those ends.

SUMMARY

To alleviate the problem of large forces operating on the controlmechanism of the retainer member, aspects of the present inventionutilize retainer member which transfers most if not all of the openingforce it counters to the valve body, while allowing the actuatingmechanism which controls the retainer member to act against a smallportion of the opening force. In some embodiments of the invention theactuating mechanism is disposed substantially at right angle to theclosing force, reducing the opening force component operating thereon tonegligible levels. As the actuating mechanism only needs to urge orrelease the retainer member using a relatively small force, fastactuation can be provided by small actuating force and correspondingsmaller actuating mechanisms.

Thus, in an aspect of the invention, there is provided a valve forcontrol of fluid flow in a fire protection system, the valve comprises avalve body defining a lower chamber having an inlet and an upper chamberhaving an outlet, and a valve seat disposed in the valve body. The valveseat surrounds a sealing port. A valve closure member, hereinafterdenoted as a clapper, is disposed within the valve body, and has abottom and a top, the bottom having a sealing surface, and the tophaving an abutment portion. The clapper is coupled to the valve body bya clapper hinge and is pivotally rotatable thereabout from a closedposition where the sealing surface contacts the seat sufficiently toimpede fluid flow from the inlet to the outlet. A retainer memberhereinafter described as an arm is rotatably coupled to the valve bodyat an arm anchored end about a hinge point, the arm has a closure endaway from the hinged end, and the arm is movable between a disengagedstate and an engaged state, wherein while the clapper is in the closedstate the closure end contacts the clapper abutment portion in at leastone abutment point, defining an arm force extending in a direction fromthe arm anchor point towards the abutment point, for maintaining theclapper in the closed position. An actuator is coupled to the arm forurging the arm from the engaged state to the disengaged state. Incertain embodiments the actuator urges the arm from the disengaged stateto the engaged state. When the clapper is in the closed state theabutment point lies in a geometrical plane parallel to the seat. Forease of understanding the plane is assumed to be separating the lowerchamber on one side thereof from the upper chamber on the opposite sidethereof. The rotational direction of the clapper from the closedposition is into the upper chamber. In many embodiments the arm anchorpoint is disposed in the upper chamber, providing several advantages tothis aspect of the invention, as described below.

Notably in most embodiments the geometrical plane is somewhat above thesealing port, and thus, strictly stating, the area below the plan mayinclude some physical portions of what may ordinarily be defined as theupper chamber, and the lower chamber, which ordinarily may be defined asextending to the sealing port, does not necessarily extend all the wayto the geometrical plan, however for brevity the division between thechambers for purposes of location and/or orientation of the elements,angles, or force directions is made somewhat arbitrarily by thegeometrical plan disclosed and defined above. The term ‘urging’ and itsvarious inflections should be extended to allow pushing, pulling,releasing, and/or rotating, and the like.

Some embodiments locate the arm anchor point substantially in-line withthe abutment point, optionally approximately parallel with a line fromthe inlet to the outlet. This arrangement offers great strength andreduced control forces.

In the engaged state, those embodiments translate substantially all ofthe opening force, imparted by the clapper to the arm closure end, tothe arm anchor point on the valve body, and a substantially orthogonalactuating force is utilized to either engage or disengage the closureend of the arm, imparting sideways movement thereto. As the actuatingforce is substantially orthogonal to the opening force, the openingforce component thereupon is negligible or nil.

When fluid having pressure is supplied to the inlet when the clapper isin the closed position, the fluid exerts on the clapper an opening forcein an opening force direction. In some embodiments the angle between theopening force direction and the arm force direction or an extensionthereof is smaller than 45 degrees. Stated differently, the includedangle between the a line congruently extending along the opening forceon both sides of the clapper, and the arm force or an extension of thearm force that may be translated laterally as required to meet suchline, will form an included angle smaller than 45°. Certain embodimentsmay utilize smaller angles, such as smaller than 30 degrees, 15 degrees,5 degrees, or smaller. Embodiments where the angle between the arm forceand the opening force are smaller than 45°, especially in embodimentswhere the abutment point surface is angled to the opening force, theeffective angle between the opening force and the arm force may beconsidered to be zero and the forces are considered parallel. In certainembodiments the actuator imparts an actuator force to the arm betweenthe arm anchor point and the abutment point. It is further noted that insome embodiments the actuator imparts the actuator force only fortransitioning the arm form engaged to disengaged state, and in otherembodiments the actuator force is imparted continuously to maintain thearm in the engaged state when the clapper is closed.

In some embodiments the arm closure end comprises a roller which is theportion of the arm in contact with the clapper abutment portion, and theabutment point is at least one point along the line of contact betweenthe roller and the abutment portion of the clapper. In certainembodiments the arm closure end comprises a ball and the ball is thecontact point between the arm and the clapper abutment portion. Incertain embodiments the arm comprises an over-the-center locking hingedlever comprising two hinged parts and a stop limiting the parts movementin one direction, such that an over-the-center swing of the hinged partstowards the stop will render the arm rigid, and over-the-center swing ofthe hinged parts in a direction away from the stop will allow the leverto hinge fully with little or no impediment. Such arrangement offers anarm which is fully locked at a small angle between the two lever parts,and an easy rotation between the two lever parts when the lever partsare moved over the hinge center in the opposite direction.

Optionally in some embodiments the abutment portion is angled to thesealing surface. In those embodiments the angle is commonly smaller than45 degrees, and in some cases is between 10 and 30 degrees. In otherembodiments the abutment portion is parallel to the sealing surface.

Optionally the arm further comprises an arm extension extending awayfrom the arm anchor point, beyond the closure end. The arm extension isoffset from the abutment point so as not to interfere with the clapper.The actuator is coupled to the arm via the arm extension. Sucharrangement will reduce the forces required to actuate the arm, and thusallow using a smaller actuator.

In optional embodiments when the clapper is in the closed state theabutment portion lies above the geometrical centroid of a plane definedby the valve seat, and in certain embodiments the abutment point lies ina line perpendicular to, and extending through, the geometrical centroidof the valve seat plane. Further optionally a lateral waterwayenlargement is provided, for avoiding waterway narrowing if the clapperfails to clear the straight waterway between the valve inlet and thevalve outlet.

In another aspect of the invention, there is provided a valve forcontrol of fluid flow in a fire protection system, the valve comprises avalve body defining a valve chamber forming a fluid path between a valveinlet and a valve outlet, the chamber having a seat disposed in thefluid path, the valve comprises a clapper having a bottom and a top, thebottom having a sealing surface, and the top having a abutment portion,the clapper being coupled to the valve body by a clapper hinge and beingpivotally rotatable thereabout from a closed position where the sealingsurface contacts the seat sufficiently to impede fluid flow from theinlet to the outlet. The valve further comprises a hinged arm movablycoupled to the valve body about a hinge point and having a closure end.Optionally the closure end having a roller coupled thereto. The arm ismovable between a disengaged state and an engaged state wherein whilethe clapper is in the closed state the closure end contacts the abutmentportion at least by the roller, for maintaining the clapper in theclosed position. Like other embodiments, the valve further comprises anactuator coupled to the arm for urging the hinge from the engaged stateto the disengaged state. In certain embodiments the actuating mechanismis capable of urging the arm from the disengaged state to the engagedstate.

In some embodiments the arm comprises at least a first and a secondelongated sections coupled by an arm hinge therebetween and rotatablethereabout. A portion of the first arm section distal to the arm hingebeing rotatably coupled to the valve body about an arm anchor point, thearm having a closure end at a portion of the second arm section distalto the arm hinge. Optionally with such arm arrangement, the arm isdisposed in an ‘over-center’ state when the arm is engaged, whichimplies that when the actuator urges the arm to the disengaged state,the hinge center crosses the arm force, i.e. a line extending betweenthe arm anchor point and the abutment end. Optionally a roller isdisposed at the abutment end.

As described above, in this context, the term ‘urging’ and its variousinflections should be extended to allow pushing, pulling, releasing,and/or rotating, and the like.

SHORT DESCRIPTION OF DRAWINGS

Some embodiments of the valve are described herein with reference to theaccompanying drawings. The description, together with the figures, makesapparent to a person having ordinary skill in the art how the teachingsof the disclosure may be practiced, by way of non-limiting examples. Thefigures are for the purpose of illustrative discussion and no attempt ismade to show structural details of an embodiment in more detail than isnecessary for a fundamental and enabling understanding of thedisclosure. For the sake of clarity and simplicity, some objectsdepicted in the figures are not to scale.

FIG. 1 depicts a cross section of one embodiment of the valve shown instandby state.

FIG. 1A depicts certain forces operating on the abutment point of thevalve in FIG. 1, and

FIG. 1B depicts a side cross section of the embodiment shown in FIG. 1.

FIGS. 2A, 2B, and 2C depict clapper and arm arrangements according tosome optional embodiments

FIGS. 3A, and 3B depict clapper and arm arrangements according to someembodiments that utilize a roller

FIGS. 4A, 4B, and 4C are enlarged views of the clapper/arm abutmentarea, showing certain optional embodiments

FIG. 5A depict cross sectional side view of the valve in an open stateand FIG. 5B depicts a cross sectional side view of valve in an openstate with a latch holding the clapper open.

FIG. 6 depicts an embodiment of an arm with an arm extension.

FIG. 7 depicts an arm/clapper interface where the roller is disposed onthe clapper

FIG. 8 depicts an example of the family of embodiments where the closurearm anchor point is below the clapper, utilizing a roller.

FIGS. 9A and 9B depict an embodiment with over-the-center hinged closurearm

FIGS. 10 A-C depicts an embodiment which offers reduced load on theclapper hinge.

DETAILED DESCRIPTION

The following describes certain embodiments by way of example tofacilitate understanding of various aspects of the invention, howeverthe invention should not be construed to be limited to only thedescribed examples.

FIG. 1 depicts a cross section of a valve 1 in accordance with someaspects of the present invention, and FIG. 1B depicts a side viewthereof. The valve has a body 10 which defines a valve chamber. Thevalve chamber may be considered as a single chamber extending within thevalve body from the valve inlet 25 to the valve outlet 30, but is moreconveniently considered as divided into an upper chamber 20 and lowerchamber 15. The valve body has a seat 35 disposed therein.

The directional terms ‘up’, ‘down’, ‘left’, ‘right’ and theirconjunctions and relations, such as upward, above, lower, below,horizontal, and vertical should be construed at their ordinary meaning,when the direction indicated by the arrow marked close to the letter Yon the vertical axis Y-Y′ axis, indicates the up direction.

A clapper 40 is coupled to the valve body 10 by a clapper hinge 55, andis capable of pivotally rotating about the hinge, into the upper chamber

The clapper has top portion and a bottom portion. The bottom portion hasa sealing surface 45, which is disposed to contact the seatsubstantially all around its perimeter, and the interface between thesealing surface and the seat forms a seal sufficient to impeded fluidflow from the lower chamber to the upper chamber, or stated differently,to prevent fluid from flowing in the fluid path between the valve inletand the valve outlet. The position in which the clapper impedes fluidflow between the valve inlet and outlet is referred to as the clapperclosed position. This interface between the seat and the sealing surfaceis considered to define the ‘seat’ in these specifications, as this isthe functional and active part of forming the seal between the upper andlower chambers.

In these specifications unintentional leaks and imperfections andparasitic forces such as friction, elasticity, and the like, areconsidered negligible in a properly operating valve, and shall not beconsidered unless specifically stated otherwise.

The clapper may rotate into the upper chamber into any number of otherpositions, until it is stopped by the valve body or by other stop, atwhich point it is considered to be in the fully open position. Arc Sc inFIG. 1A indicates the general swing of the clapper. The clapper mayassume any number of intermediate positions between the closed and afully open positions, but generally any position where fluid isintentionally allowed to flow through the clapper/seat interface isconsidered open

The valve chamber forms a controlled fluid flow path from the valveinlet, and while the valve is in an open state, via the lower chamber,passing the seat, via the upper chamber, and continuing to the valveoutlet.

When the valve is deployed in a firefighting system, fluid underpressure is coupled to the valve inlet, and the clapper in its closedposition prevents the fluid from flowing past the clapper-seat interfaceto the valve outlet, thus the firefighting system is in standby mode,and the valve is said to be in closed state, or equivalently, in standbystate.

When in standby state the fluid at the lower chamber exerts an openingforce on the clapper. The opening force magnitude is a function of thearea of the sealing force and the fluid pressure. The combined openingforces operating on the whole surface of the clapper exposed to fluidpressure, may be represented by an equivalent force vector (denotedhereinafter as central vector or F_(CO)) located at the centroid of allopening forces operating on the clapper. In general, such central vectorF_(CO) would be located at the geometrical centroid of the seat anddirected perpendicular thereto in the opening direction. By way ofexample in FIG. 1A, while the pressure is distributed across the sealingsurface, a portion of the opening force F_(CO) is acting on the clapperhinge 55, and a component of the force, depicted by the vertical lineF_(o), acts on the clapper end opposite the hinge in the openingdirection. The force F_(O) is the vertical component of F_(co) at theabutment point on the rotation arc S_(c) of the clapper at the instantof transition from the closed state. The opening force F_(O) may be veryhigh and in most cases far exceeds the force required to rotate theclapper to an open position against the force of gravity or any spring,and thus a closing force is required to counteract the opening force,and maintain the clapper in the closed state. It is noted that thelocation of F_(co) may differ from the geometrical centroid if thebottom surface of the clapper is not planar, and those skilled in theart would readily recognize how to calculate the equivalent vector usingwell known mechanical physics principles.

The clapper top has an abutment portion 50, where such closing forceF_(c) is applied. The abutment portion is most often disposed on theportion of the clapper distal from the clapper hinge, to allow reductionof the magnitude of the closing force and the force operating on thehinge, however, in certain embodiments, as depicted for example by FIG.9, the abutment portion is placed so as to reduce the portion of theF_(CO) force which is applied to the clapper hinge 55.

A retainer member embodied as an arm 60 is provided to selectively applythe closing force Fc. The arm in the depicted embodiment is movablyanchored directly or indirectly to the valve body, such that the arm mayhinge about a hinge point 65. The arm is movable between a disengagedstate, and an engaged state in which the arm acts against at least aportion of the clapper opening force denoted by F_(o). The arm extendsto a closure end 70, which is a portion of the arm extending away fromthe arm anchor point 65 towards the clapper abutment portion when theclapper is in the closed position, and the arm is engaged. The armclosure end contacts the clapper abutment portion in at least oneabutment point 75. The term ‘abutment point’ should be construed as anarea of interface between the clapper in the closed position and the armclosure end in the engaged state, and does not necessitate a singlegeometrical, dimensionless point. Generally the point of contact betweenthe arm closure end and the clapper abutment portion closest to theclapper hinge is considered as an abutment point, as it counteracts thehighest opening force countered by the arm. However more than oneabutment point may exist with pressure applied therethrough between theclapper abutment portion and the arm closure end.

When the arm is engaged with the clapper abutment portion, the armcounteracts the opening force or a component thereof, operating at theabutment potion, and thus the arm may be considered to apply an armclosing force. Often the arm closing force is equivalent or closelyrelated to the closing force, and at least a large component of the armclosing force is translated into the closing force F_(C) which actsagainst the opening force F_(O), and thus against the central forceF_(co) or a component thereof if the arm is engaged away from thecentroid or the seal.

A geometrical plane parallel to the seat and containing the abutmentpoint divides the valve body to the upper chamber 20, which is thechamber into which the clapper rotates when transitioning from theclosed position, and the lower chamber 15 which is directed from thedividing plane towards the valve inlet, opposite the up-arrow on theY′-Y axis. The geometrical plane is depicted in FIG. 1 by the dashedline extending from X to X′

FIG. 1A depicts simplified force distribution about the abutment pointin the valve of FIG. 1. While other latching and abutments arrangementsare disclosed below, the forces or their equivalents generally operatein similar directions, but may be translated to other location.Moreover, while certain of the depicted forces may be equivalents ofvarious force components, basic force equivalents will result in forcessimilar to the depicted forces. Notably, the depicted force indicateonly directions, and are not necessarily proportional to the relative orabsolute magnitude of the forces or force components.

In certain embodiments, the arm anchor point 65 is disposed in the upperchamber. In a number of those embodiments the anchor point is disposedsubstantially above the abutment during standby state, such that the armanchor point 65 is substantially perpendicular to the dividing plane,and disposed above, or in close proximity to, the abutment point 75.Placing the latch anchor point above the abutment point results in thelatch force acting directly against the opening force F_(O) or avertical component of the opening force at the abutment portion, andthat force is directly transferred to the latch hinge point 65. As theopening force F_(o) may be considered as being directly translated tothe valve body at the arm anchor point, such embodiments offer very highstrength.

In some embodiments the anchor point 65 is horizontally offset fromabove the abutment point such that the arm closing force L_(f) and thevertical component of the opening force F_(O) form an angle αtherebetween, such as shown by way of example in FIGS. 4B and 4C.Embodiments where the effective angel α is smaller than 12 degrees havenegligible effect on the vertical force distribution, and may forpractical purposes be considered as equivalent to an anchor point beingdirectly above the abutment point. All effective angles α lower that 45degrees are explicitly considered. Effective angles α larger than 45degrees present substantial horizontal force component and thus 45degrees is considered a practical, if not physical, limit of the angledesired between the arm force L_(f) and the vertical component of theopening force F_(O).

In the embodiment depicted in FIG. 1, a hinge is utilized to anchor thearm to the valve body, but those skilled in art would recognize thatother anchoring arrangements such as a ball and socket joint, saddlejoint, and the like, may be equivalently utilized.

An actuator 80 is anchored to the valve, or forms a portion thereof, andacts as a control mechanism for the arm, and thereby for the valve. Inthe embodiment of FIG. 1 the actuator is coupled to the arm via apushrod 85. The actuator is disposed to act on the arm and to eithermaintain the arm in engaged state, or to urge the arm into thedisengaged state. In certain embodiments the actuator may further act torelease or move the arm from the disengaged state to the engaged state.In certain embodiments, the arm may also act on the clapper, to bring itback into the closed state.

The force applied by the actuator to the arm is enumerated, and oftenreferred to in these specifications, as F_(A). The mode of operation isdictated by the choice of the arm arrangement against the clapper.

It is an important feature of the aspect of the invention depicted inFIG. 1 and in other selected embodiments, that F_(A) is disposedsubstantially perpendicularly to the opening force F_(O), thus in aprecisely orthogonal system no opening force component is imparted tothe actuator, yet an application of actuator force which is orthogonalto the opening force would displace the arm and allow the clapper totransition to an open state.

Various structures are possible for the abutment area. FIGS. 2A-C, 3Aand 3B, 4 A-C, 6, 7, 8 9A-B, and 10A-C depict schematically severalexemplary arrangements of the interface between the arm 60 and theclapper, while the valve is in standby state. For clarity these figuresshow schematically only few elements of the valve, primarily the clapperwith its hinge, the arm and its hinge point, and an optional actuatorlink. The figures are drawn schematically for illustration purposes, andno proportional or dimensional information is provided thereby.

FIG. 2A depicts an arrangement where the latch hinge point is disposedabove the abutment point 75 of the arm closure end 70 with the clapperabutment portion 50. The arm 60 prevents the clapper from rotating intothe upper chamber as the arm closure end 70 counteracts the openingforce exerted by the fluid on the sealing surface 45. In this examplethe latch force L_(f) is congruent with the closing force F_(C), anddirectly counteracts the opening force F_(O), by transferring it to thevalve body 10 via the arm anchor 65. Moving the arm sideways either leftor right, such as by applying a force via actuator link 85 will causethe arm 60 to swing about the arm anchor 65, releasing the clapper 40 topivot about the clapper hinge 55, in response to the opening forceF_(O). As link 85 is disposed substantially perpendicularly to theopening force F_(O), no portion of the opening force is transferred toit, and thereby to the actuator 80.

FIG. 2B depicts a similar configuration to the configuration of FIG. 2A,however in this embodiment the clapper abutment area 50 forms an angle αto the sealing surface. The angle α is depicted in FIG. 4A, althoughFIG. 4A depicts a different abutment arrangement. In such arrangementthe clapper imparts some horizontal force denoted F_(H) in FIG. 1A tothe arm 60 and thereby to the actuator link 85 and to the actuator 80.Those skilled in the art would recognize that this force is a componentof the total opening force acing on the clapper. In such embodiment theactuator is required to maintain a force F_(A) opposing the horizontalforce F_(H), and removal of the actuator force F_(A) will allow the armto swing to the disengaged state and the clapper to swing open.

The arm 60 in the embodiment depicted in FIG. 2B also depicts anoptional construction where the arm anchor 65 is horizontally offsetfrom the abutment point. In contrast to the embodiment of FIG. 2A wherea line drawn between the arm anchor point 65 and the abutment point 75would be substantially perpendicular to the dividing plane, in theembodiment of FIG. 2B the line extending between the arm anchor 65 andabutment point 75 forms an angle to the vertical. Such angle is depictedin FIGS. 4B and 4C, again the different closure end designnotwithstanding, and is denoted as angle α. It is noted that embodimentsmay use different arm closure end configurations and different armanchor positions, alone or in combination, and the specific embodimentsare dictated by engineering and design choices.

In the embodiment depicted in FIG. 2C the arm anchor point 65 is againshown perpendicularly to the clapper abutment point 75, but the armclosure end 70 has an angled face and the abutment point is disposed onthe angled face. Similar to the embodiment in FIG. 2B, this arrangementresults in a horizontal force F_(H) acting on the arm, and the actuatorapplies force F_(A) to maintain the arm in the engaged state.

As stated above, the different dispositions of the latch and theabutment are a matter of engineering choice to provide differentdistribution of forces as desired by the designer. Thus, by way ofexample, in the configuration of FIG. 2A the clapper opening force isborne by the arm 60, and translated thereby to the arm anchor point 65,and therefrom to the valve body 10. Therefore, no horizontal forcecomponent of the opening force urges the arm to open sideways. In thisarrangement, the actuator does not need to apply any force to keep thearm engaged with the clapper, and the actuator must urge the arm intodisengaged state to allow the valve to open. In contrast, in theembodiment depicted in FIGS. 2B and 2C a component of the opening forceis horizontal, and the actuator or other mechanism must counteract thisforce to maintain the arm closure end 70 engaged with the clapperabutment portion 50. With proper selection of the angled surfaces, orthe disposition of the arm anchor, a desired balance may be achieved forthe actuator force, and the proportions in the actuator force versus thehorizontal component of the opening forces contribute to armdisengagement.

The retainer mechanisms of FIGS. 2A-C already present improvement overthe present state of the art. However, for further control of theopening forces certain embodiments of the invention utilize a rollinginterface between the arm closure end 65 and the clapper abutmentportion 50. Rolling interface may be achieved by a roller rotatableabout a roller shaft or pin. The term roller will also relate to a ball.The roller may be disposed on the arm or on the clapper. The roller isdisposed to rotate during the disengagement of the arm closure end fromthe clapper. The use of a roller provides significant mechanicaladvantage as it offers lower friction resistance between the closure armand the clapper, thus a roller offers higher reliability, shorterdisengagement times, ability to withstand higher opening forces, andlower actuator force required for disengagement.

FIG. 3A depicts a first embodiment of an arm equipped with a roller. Thesimilarity of the structure and the operating forces between theembodiments of FIG. 2A and FIG. 3A is clear, however the embodiment ofFIG. 3A requires much lower actuator force F_(A) to dislodge the closurearm to a disengaged state. FIG. 3B depicts an embodiment similar incertain respects to the embodiment depicted in FIG. 2C, however thisembodiment too enjoys the aforementioned advantages offered by theroller.

FIG. 4A depicts an enlarged view of the portion of the latchingmechanism of FIG. 3B. The abutment portion 50 is emphasized by a heavyline. The angle β between the abutment portion and the plane parallel tothe sealing surface 45 is shown. The force exerted by the clapper on theroller operates at a right angle to the abutment portion 50 and is thuspointed at the roller pin 95, where the force is divided between ahorizontal component and the arm force extending between the arm anchorpoint and the roller pin. The horizontal component proportional to sinβ, will be transformed to a horizontal component which will act to urgethe arm to the left. This force requires an opposing force to maintainthe arm in engaged state.

It is noted that while the embodiments of 3A and 3B are shown with thearm anchor point being substantially directly above the abutment point,designs with horizontal offset are also considered and will be clear tothe skilled in the art in view of the teachings of these specifications.

FIG. 4B depicts an example of an arm engagement where the arm anchorpoint is disposed at angle α between the vertical and a line extendingbetween the arm anchor and the roller pin 95. A force calculation willshow that the horizontal force component on the arm will be reduced as agrows until it reaches a perpendicular angle to the abutment portion 50,and after that point the horizontal force will be reversed, pullingincreasingly to the right.

FIG. 4C depicts an enlargement of the arm arrangement where the armanchor point 65 is disposed horizontally closer to the clapper hinge 55,or stated differently, at standby state the arm 60 extends at an angle αbeyond the vertical towards the clapper hinge, which for conveniencewill be referred to as a negative α. The horizontal force F_(H) urgingthe arm to the left is a function of sin β, and assuming a small β, theforce will also be small. Therefore the actuator force F_(A) requiredwill also be small. It is noted that with very small forces parasiticforces such as the friction between the roller and the roller pin 95should be considered. However negative alpha arrangements exhibit anadvantage: during the valve standby state, where the clapper is closedand the arm is engaged, almost all the opening force is transferred tothe arm anchor point 65. However during transition from the engagedstate the horizontal component operating on the roller and urging it topush the arm to the left grow rapidly, and therefore while a small, ifany, force is required to hold the arm in engaged state, a strong andrapidly growing component of the large opening force operates todisengage the arm after it begins to move, until the closure enddisengages from the clapper. Such arm arrangement allows minimal holdingforces and very rapid opening of the valve as the arm disengagementaction utilizes at least in part the rapidly growing component of theopening force. Negative α is most effective at small β values as therate of change of the sin function is at its greatest close to zerodegrees.

FIGS. 5A and 5B depict side view cross sections of the valve of FIG. 1.FIG. 5A depicts the valve at an activated state. It is seen that theclapper is rotated away from the seat and fluid can flow relativelyfreely between the inlet and the outlet. Notably, when the clapperrotates upwardly it deflects the reset stop 150 upwards to allow theclapper to swing past it. The reset stop may then free fall into itsrest position, as shown.

FIG. 5B depicts the valve at rest, but the clapper is partially open.This state, is normally reached when the valve is activated and thefluid supply is disconnected or the incoming fluid pressure drops belowa sufficient level to support the clapper in the raised position. Theclapper is prevented from dropping to the full closed state by the resetstop 150. Optionally, reset stop 150 is hinged on the closure arm anchorpoint 65. Such arrangement reduces manufacturing costs and places thereset stop in a convenient proximity to the clapper trajectory. Thereset stop 150 may be moved upward by applying pressure on reset plunger155, which will result in the reset stop 150 rotating about the armanchor point 65, rotating the clapper upward. When the reset stop 150passes past the clapper edge, the clapper falls back onto the valve seat35, the arm 60 may be reset to its engaged position against the clapperabutment point, fluid pressure restored, and the system will be armedagain ready for its next deployment.

In certain embodiments a reset stop 150 is not provided, and the clappercloses by force of gravity, by a spring or by an actuator afterdisconnection or discontinuance of the fluid supply.

Following closure of the clapper, reverse actuation of the actuator willreturn the clapper to standby state by engagement of the arm closure endagainst the clapper abutment point. In certain embodiments the actuatingmechanism is capable of urging the arm from the disengaged state to theengaged state causing closure of the clapper. After the clapper has beenclosed and the arm returned to an engaged state, firefighting fluidpressure may be resumed and the system will again be armed and ready tofight fire.

FIG. 6 depicts schematically a closure arrangement where the closure arm60 is coupled to the actuator via an extension arm 105 extending belowthe abutment point. Such arrangement may be used to reduce the actuatorforces.

The actuator link is but one option through which the actuator 80 mayexert force on the arm 60. The coupling between the actuator and the armmay be by direct contact, levers, push rods, cables, wires, and thelike. The coupling may be mechanically coupled to the arm or theactuator, or based on intermittent contact at specific times. Thoseskilled in the art would readily recognize numerous ways to establishthe coupling such that force may be applied by the actuator to the arm,to a portion thereof, or to an intermediate structure couplingtherebetween.

FIG. 7 depicts schematically an optional arm arrangement where a roller91 is disposed on the clapper 40 and acts as the abutment portion 50. Inthe standby mode the closure end 70 of arm 60 contacts the roller 91 atan abutment point 75.

It is important to realize the advantages of a roller at the abutmentpoint to the reliability of the valve operation. These advantagesfurther extend to embodiments where the arm anchor point is in the lowerchamber. One example embodiment is depicted in FIG. 8, where the armanchor point 65 is disposed below the clapper, and the arm is configuredto rotate thereabout for releasing the clapper. Those skilled in the artwould recognize the rotational forces acting on the arm via the inclinedabutment portion 50 of the clapper, to the roller 90, and via the armbody, however a placement of the arm roller on an abutment portion ofany configuration as described above is also considered. Other examplesof the use of rollers as the point of abutment would be clear to thoseskilled in art in view of the known art and the teachings of thesespecifications. In certain embodiments, numerals 90 and/or 91 may alsorefer to a ball.

FIGS. 9A and 9B depict an optional arm 60 structure. The arm comprises ahinged lever having two sections, 60A and 60B respectively, coupled by ahinge 115 therebetween and rotatable thereabout. FIG. 9A depicts the armin the engaged state and FIG. 9B depicts the arm in the disengagedstate. The two parts 60A and 60B are rotatable relative to each otherabout the hinge 115. When the two sections are collinear and oppositelyextending from the hinge they are said to be “on-center”. The arm 60further comprises a mechanical stop 110, disposed to limit the relativerotation of two sections when rotating in one direction termed theblocked direction from the on-center position. The two sections are freeto rotate over significantly larger arc when rotating in the oppositedirection to the blocked direction, termed the non-blocked direction.Oftentimes the arc reaches and sometimes exceeds 90°. When the twosections are rotated farther than the on-center state towards theblocked side, they are said to be locked, and when the arm is incompression, a force is required to move the two sections ‘over thecenter’ towards the non-blocked direction. When the arm sections arelocked, the arm becomes very rigid, and capable of carrying very largeloads. FIG. 9A depicts two sections 60A and 60B of the arm 60 in lockedstate, the arm engaging the clapper 40 and acting to translate theopening forces operating thereupon to the closure arm anchor 65. FIG. 9Bdepicts the over-the-center lever in the disengaged state, after theApplication of relatively small actuating force in the directionindicated by the arrow marked on actuator link rod 85 causes the two armsections to go ‘over-the-center’ and the arms can then fold towards eachother in the opposing direction, and clear the clapper, which may thentransition to an open state. This arrangement is yet one more example ofan arm arrangement where the arm as a whole is stable, where no force isrequired by the actuator to maintain the valve in standby state, andwhere the opening force F_(O) and the actuating force F_(A) are mutuallyisolated. A roller or a ball similar to those denoted as 90 and 91 mayalso be utilized.

FIGS. 10A-C are directed towards an embodiment which provide reductionof the forces operating on the clapper hinge 55. In the otherembodiments disclosed hereabove the clapper opening force F_(CO) issubstantially divided between the abutment point 75 and the clapperhinge 55. The embodiment in FIG. 10A places the clapper abutment portion50 away from the clapper edge, and in some embodiments, above a point ator near the force centroid 42 of the clapper, or stated differently,along the axis of the central opening force F_(CO). Those skilled in theart would recognize that a force acting in the opposite direction toF_(CO) would distribute equally over the seat, and as such pointsoutside the seat would be subject to minimal if any forces. Such designremoves the force component which acts on the clapper hinge 55 in theabove depicted embodiments, and thus enables use of a smaller clapperhinge and hinge supports thus providing reduction of at least some ofthe valve lateral dimensions.

In FIG. 10A the abutment portion is displaced above the rest of theclapper by abutment extension 178, so as to allow the clapper to clearthe arm 60 as it swings to the open state, as seen schematically in FIG.10B which depicts a cross section of a valve embodiment utilizing aclapper and hinge arrangement in accordance with FIG. 10A, the valveshown in the open state. Notably, the arm 60 may be made sufficientlylong, such that when the clapper swings into the open state, it clearsthe arm anchor point 65, while displacing the arm 60, avoiding the needfor an abutment extension 178. Yet another optional feature is shown inFIG. 10C, where the retainer mechanism is displaced by the clapper,however the clapper does not clear the arm anchor point 65, and theclapper swing is stopped thereby, or by another mechanical stop such asany part of the latch mechanism. In such embodiments it may be desirableto provide lateral waterway enlargement 98 about the clapper, so as tomaintain full flow of the valve, and avoid flow restriction by theclapper which is restricted from swinging completely out of thewaterway. Notably such lateral waterway enlargement may be desired inother embodiments as well if any portion of the retainer arrangementdoes not allow the clapper to swing fully out of the main waterway. Theactuator 80 depicted in the figures is a diaphragm 100 actuator. Theactuator is coupled by optional rod 85 to the arm. However the skilledin the art would recognize that other actuators may be utilized. By wayof example, certain aspects of the invention are beneficial, and extendto, electrically or pneumatically operated valves, wherein otheractuators such as a fluid driven or electric motor, a solenoid, apiston, a screw, and the like, exert the desired pressure to push, pull,or rotate the arm.

The depicted examples show horizontally disposed actuator, however theactuator may assume any direction that will exert sufficient properforces to the arm, either to dislodge the arm from the engaged state, orto oppose the force F_(h) and maintain the arm in place. Notably, incertain embodiments utilizing actuators at different inclinations, theforce direction in the examples need to be adjusted to account for thegeometries used. Such adjustments are explicitly considered and theinvention and claims extend to such embodiments.

The reader is again reminded that the above supplied drawings areprovided for illustration purposes, and that the drawings and theircomponents are not necessarily drawn to scale, neither are forces shownto scale, but more to indicate broad general directions.

In this disclosure, unless otherwise stated, adjectives such as“substantially” and “about” that modify a condition or relationshipcharacteristic of a feature or features of an embodiment of the presenttechnology, are to be understood to mean that the condition orcharacteristic is defined to within tolerances that are acceptable foroperation of the embodiment for an application for which it is intended.Furthermore, unless otherwise stated the terms used in this disclosureshould be construed as having tolerances which may depart from theprecise meaning of the relevant term but would enable the invention orthe relevant portion thereof to operate and function as described, andas understood by a person skilled in the art.

It will be appreciated that the invention is not limited to what hasbeen described hereinabove merely by way of example. While there havebeen described what are at present considered to be the preferredembodiments of this invention, it will be obvious to those skilled inthe art that various other embodiments, changes, and modifications maybe made therein without departing from the spirit or scope of thisinvention and that it is, therefore, aimed to cover all such changes andmodifications as fall within the true spirit and scope of the invention,for which letters patent is applied.

1. a valve for control of fluid flow in a fire protection system, thevalve comprises: a valve body defining a lower chamber having an inletand an upper chamber having an outlet; a valve seat disposed in thevalve body, the valve seat defining a sealing port; a clapper having abottom and a top, the bottom having a sealing surface, the top having anabutment portion, the clapper being coupled to the valve body by aclapper hinge and being hingedly rotatable thereabout from a closedposition where the sealing surface contacts the seat sufficiently toimpede fluid flow from the inlet to the outlet, to at least partiallyopen position; an arm rotatably coupled to the valve body about an armanchor point, the arm having a closure end, the arm being movablebetween a disengaged state and an engaged state wherein while theclapper is in the closed state the closure end contacts the abutmentportion in at least one abutment point, defining an arm force extendingin a direction from the arm anchor point towards the abutment point, formaintaining the clapper in the closed position; an actuator coupled tothe arm for urging the arm or for allowing the arm to move from theengaged state to the disengaged state; wherein when the clapper is inthe closed state the abutment point lies in a geometrical planesubstantially parallel to the seat, the geometrical plane separating thelower chamber on one side thereof from the upper chamber on the oppositeside thereof, the rotational direction of the clapper from the closedposition being initially towards the outlet; wherein the arm anchorpoint being disposed in the upper chamber; and, wherein when fluid underpressure is supplied the inlet and the clapper is in the closed positionthe fluid exerts thereupon an opening force having a direction, andwherein the included angle between a line congruent with the openingforce and a line congruent with the arm force direction or a paralleltranslation thereof is smaller than 45 degrees.
 2. A valve as claimed inclaim 1, wherein the actuator imparts an actuator force to the armbetween the anchor point and the abutment point.
 3. A valve as claimedin claim 2 wherein the arm force direction is perpendicular to thegeometrical plane.
 4. A valve as claimed in claim 2, further comprisingan arm roller coupled to the abutment portion or the closure end,wherein the at least one abutment point is disposed on the roller.
 5. Avalve as claimed in claim 4 further comprising an arm ball coupled tothe abutment portion or the closure end, wherein the at least oneabutment point is disposed on the ball.
 6. A valve as claimed in claim4, wherein the arm force direction is substantially perpendicular to thegeometrical plane.
 7. A valve as claimed in claim 4, wherein theabutment portion is angled to the sealing surface.
 8. A valve as claimedin claim 1, wherein the abutment portion is angled to the sealingsurface.
 9. A valve as claimed in claim 1 wherein the arm furthercomprises an arm lever extending away from the arm anchor point beyondthe closure end, and offset thereto.
 10. A valve as claimed in claim 1,wherein the arm force is substantially perpendicular to the geometricalplane.
 11. A valve as claimed in claim 10, wherein the abutment portionis angled to the sealing surface.
 12. A valve as claimed in claim 1,wherein in the engaged state the arm force forms an angle between the atleast a component of the opening force normal to the abutment portion atthe at least one abutment point, such that when the arm is moved to theengaged state the arm force would momentarily become parallel to thecomponent of the opening force.
 13. A valve as claimed in claim 1,further comprising an arm roller coupled to the abutment portion or theclosure end, wherein at least one abutment point is disposed on theroller.
 14. A valve as claimed in claim 1, further comprising an armball coupled to the abutment portion or the closure end, wherein atleast one abutment point is disposed on the ball.
 15. a valve forcontrol of fluid flow in a fire protection system, the valve comprises:a valve body defining a lower chamber having an inlet and an upperchamber having an outlet, a valve seat disposed in the valve body aclapper having a bottom and a top, the bottom having a sealing surface,and the top having an abutment portion, the clapper being coupled to thevalve body by a clapper hinge and being hingedly rotatable thereaboutfrom a closed position where the sealing surface contacts the seatsufficiently to impede fluid flow from the inlet to the outlet, to atleast partially open position; a hinged arm rotatably coupled to thevalve body about an arm anchor point the arm having a closure end andbeing movable between a disengaged states and an engaged state, whereinwhen the clapper is in the closed state and the arm is in the engagedstate, the arm and the abutment portion contact each other in at leastone abutment point for maintaining the clapper in the closed position;an arm roller or ball coupled to the abutment portion or the closureend, wherein the at least one abutment point is disposed on the rolleror ball; an actuator coupled to the arm for urging the arm or forallowing the arm to move from the engaged state to the disengaged state.16. A valve for control of fluid flow in a fire protection system, thevalve comprises: a valve body defining a lower chamber having an inletand an upper chamber having an outlet, a valve seat disposed in thevalve body a clapper having a bottom and a top, the bottom having asealing surface, the clapper being disposed within the valve body andbeing movable from a closed position where the sealing surface contactsthe seat sufficiently to impede fluid flow from the inlet to the outlet,to at least partially open position, the clapper top having an abutmentportion disposed substantially above the geometrical centroid of thevalve seat when the clapper is in the closed position; an arm rotatablycoupled to the valve body about an arm anchor point, the arm having aclosure end, the arm being movable between a disengaged state and anengaged state wherein while the clapper is in the closed state theclosure end contacts the abutment portion in at least one abutmentpoint, defining an arm force extending in a direction from the armanchor point towards the abutment point, for maintaining the clapper inthe closed position; an actuator coupled to the arm for urging the armfrom the engaged state to the disengaged state; wherein when the clapperis the closed state the abutment point lies in a geometrical planeparallel to the seat, the plane defining a plane lower side on one sidethereof a plane upper side on the opposite side thereof; and, whereinthe arm anchor point being disposed on the upper side of the plane. 17.A valve as claimed in claim 16 wherein the clapper abutment portion isdisposed such that a line perpendicular to the valve seat and passingthrough the valve seat centroid would extend substantially through theabutment point, and wherein the clapper abutment portion extendssufficiently into the upper chamber to allow the clapper to clear thearm or a portion thereof during transition from a closed state to afully open state.
 18. The valve as claimed in claim 17, wherein theclapper is being coupled to the valve body by a clapper hinge and beinghingedly rotatable thereabout.
 19. A valve as claimed in claim 16,further comprising a lateral waterway enlargement, extending laterallyfrom the waterway in a direction at least partially away from theclapper edge.
 20. A valve as claimed in claim 16, further comprising anarm roller or ball coupled to the abutment portion or the closure end,wherein the at least one abutment point is disposed on the roller orball.